Toni Collette had told her agent that she didn't want to do any more heavy, dark films and only wanted to do comedies, but she loved the "Hereditary" script so much she couldn't turn it down.

Ari Aster requested that Alex Wolff and Milly Shapiro go out to eat in character a few times, and they would sit for up to three hours in silence while Milly wouldn't speak and Alex would try to get her to talk.

Toni Collette has called Ari Aster the most prepared director she's ever worked with. She praised him for practically having the full movie already shot and edited in his head two years before they started filming.

(at around 1h 6 mins) To make the chalkboard write on itself, the special effects team put a magnet in the chalk and put a magnet on the other side of the chalkboard to make the chalk move--it was very difficult to get a small magnet inside the chalk and make it write smoothly.

Ari Aster liked Utah for the film because he thought its mountains are beautiful and breathtaking, but also menacing and ominous.

According to Alex Wolff, the original cut of the film could have easily pushed over 3 hours. The cut footage mostly consists of more family dialogue.

Ari Aster wanted any effect that could be done practically to be done that way, instead of in post production.

Ari Aster wanted to go for scares that were emotionally justified, rather than solely leaning on traditional horror "jump scares."

With Hereditary, Ari Aster wanted to "make a film about suffering that took suffering seriously".

Ari Aster wrote detailed biographies and backstories for all of the characters before even writing the screenplay.

The producer said that it worked out well that Gabriel Byrne and Alex Wolff had worked together, and Alex and Milly Shapiro knew each other from school, because it made Toni Collette the outsider, which mirrored Annie's character and feelings of alienation within her own family.

The film was shot in 32 days.

Composer Colin Stetson found inspiration for the score through the sounds of "water and animals while walking around in pitch-black night."

The entire interior of the Graham house was built on a sound stage.

For Ari Aster, Hereditary is equally inspired by family dramas (Ordinary People (1980), The Ice Storm (1997), In the Bedroom (2001)) as it is by classic horror films (Rosemary's Baby (1968), Don't Look Now (1973), The Innocents (1961)).

The house was constructed completely on sets on a soundstage in Utah in order to follow Ari Aster's shot list. They needed to be able to remove walls and ceilings in order to shoot the rooms to look exactly like the miniatures.

Ari Aster has 10 screenplays written he hopes to direct over the course of his career.

Production designer Grace Yun did research on pagan rituals and cults to prepare for designing the sets.

Production designer had to work simultaneously with miniaturist to ensure the Graham house and the miniature house were exactly the same.

The special effects team had to learn how to do effects they'd never done before, such as making a candle light itself.

Many of the cast and crew view the film as a family drama more than a horror movie.

This film is director Ari Aster's feature debut.

Toni Collette stated that she went to the gym a lot during shooting because she needed to be moving around during such an arduous filming process.

(at around 14 mins) In Peter's first scene at school, the words "Escaping Fate" is on the chalkboard with the teacher discussing it. This is a reference to Halloween (1978), where the main character discusses the same thing in class. Appropriately, this movie was released the same day as the trailer for Halloween (2018).

Both Alex Wolff and Milly Shapiro attended Professional Children's School, and already knew each other before the film.

Production designer wanted to play with the idea of "sacred geometry"--triangle (Annie, Peter, Charlie), square (introduces Steve's character, home, groundedness), circle (infinite, genesis, Ellen) - all different shapes embedded within the design of the set. If you look closely, the second floor hallway has squares and triangles carved into it.

The movie contains around 85 minutes of music, and Colin Stetson worked 16-hour days at times in order to complete it.

Alex Wolff said that this film was more demanding than anything he'd ever done.

Toni Collette said one of her most memorable moments on set was being doused in water fully clothed for the paint thinner scene.

Gabriel Byrne played Alex Wolff's dad previously in the HBO TV show In Treatment (2008)-- they have joked that every seven years they're going to play father and son.

Ari Aster also designed a 75-page shot list for the cinematography before they even had locations scouted.

The primary direction Ari Aster gave composer Colin Stetson for the score was to make it "feel evil."

Ari Aster was heavily influenced by the film The Cook, the Thief, His Wife & Her Lover (1989).

Ari Aster had originally wrote this film to be a straight up family drama, dealing with the grief and loss one experiences with the death of close family members, but Aster saw the potential of turning the film into a horror story and rewrote the script to what it is now. Had this remained a family drama, Midsommar (2019) would have been his first horror film like he initially intended it to be.

Originally, Steve Newburn had been contacted about providing the makeup effects for Hereditary, but after he had read the script, he had an idea. Steve contacted the production and asked, "Hey, what about miniatures? Who's doing that?" In fact, the production had been having trouble finding someone to handle the important miniatures for the film, so Newburn and company took on that responsibility as well.

Toni Collette (Annie) is 22 years younger than her on-screen husband, Gabriel Byrne.

Toni Collette doesn't actually like horror films which is what made her hesitant at first to act in the film. The only reason she accepted her roles in Fright Night (2011) and Krampus (2015) were because she saw them more as black comedies rather than horror films.

This was the fourth A24 movie to get a wide release after The Witch (2015), Free Fire (2016) and It Comes at Night (2017).

Alex Wolff and Milly Shapiro also had to go out in character and buy Milly a sweatshirt, and Alex had to figure out what kind of sweatshirt she wanted.

Ari Aster has been writing screenplays from a very young age, but eventually realized he would want to be the one to direct what he'd written.

Alex Wolff said that Gabriel Byrne is one of his favorite people he's ever gotten to work with.

Once they found the cemetery surrounded by snow peak mountains, they knew they had found the location for the film.

Ari Aster started building a network of potential collaborators for this film years before the project had been greenlit.

Feature film debut of Milly Shapiro.

Alex Wolff decided to go method for this film and insisted on being referred to as 'Peter' during production. After filming his very last scene, he symbolically introduced himself to the crew as 'Alex.'

Alex Wolff is a huge horror movie buff, which is what convinced him to accept his role in the film.

With the definition of its maker, Ari Aster, Hereditary is a film about suffering.

The fact that Toni Collette did not land any Golden Globe or Academy Award (Oscar) nominations for her performance in this film was generally regarded as one of the worst snubs of the year.

Included among the "1001 Movies You Must See Before You Die", edited by Steven Schneider.

The production designer designed pieces for the house that were meant to be pieces from Annie's previous art collections.

Ari Aster regularly listened to composer Colin Stetson's earlier music while he was writing the script.

Toni Collette also stars in the Showtime series United States of Tara (2009), featuring Toni as a woman with dissociative identity disorder trying to raise her children, maintain her marriage and discover why she may be suffering from DID.

Colin Stetson saw the score as its own character in the film.

Filmed in Utah Film Studios in Park City Utah

The film premiered on January 21, 2018 at the 2018 Sundance Film Festival in the Midnight section.

Director of photography Pawel Pogorzelski was Ari Aster's classmate at the American Film Institute Conservatory.

Colin Stetson used his own vocals in his score.

Colin Stetson, the composer and a saxophonist, has toured with Arcade Fire, Bon Iver, TV on the Radio, Tom Waits.

Ari Aster reached out to composer Colin Stetson two years prior to production.

Toni Collette and Alex Wolff share a birthday (November 1).

There are four or five primary scenes from Annie's life plus a half-dozen others that represented previous events not seen in the movie. The previous gave Steve Newburn more freedom design-wise since they were not tied to actual locations. Hereditary's exteriors were shot on location in Utah; the interiors were filmed on stages constructed in Toronto. The miniatures required included Charlie's schoolroom, Annie's mother's hospice, and a multi-level version of the family house built atop other rotting and collapsing houses. What do you think Sigmund Freud would say about that? While drawing concepts for these dioramas, Steve communicated with the director by email several times a day and by Skype every other day. The production supplied details for the miniatures, from both the location and studio environments. These included measurements, multiple angles of props, paint splotches, along with images and samples of wallpaper and hardwood floors. Some of the details were handcrafted while others were 3D printed. Most of the miniatures were built from balsa wood and basswood and other traditional hobby and dollhouse materials. The furniture was handmade with the exception of the more ornate parts like legs. In fact, thousands of 3D-printed parts were produced. Everything from the table and chair legs to ornate chandeliers and light fixtures. Even the toys in the preschool diorama were 3D printed. The carpets inside the miniature rooms were not made of actual carpet; they were screen-printed. It took a miniatures crew of about ten people two months to build all of the pieces required. Armed with boxes of set dressing for the dioramas, Steve and crew arrived at the shoot only to discover that they had done their jobs too well. Sometimes the production asked for some of the details to be removed from the dioramas. Steve recalls being told, "It doesn't need to be that detailed; it's a work in progress." In the end, Steve was very happy with the way the miniatures were shot and how they were featured so prominently in the film. As for working with Milly Shapiro, Steve said that the young actor was incredible. And how was it working with Toni Collette? "Toni is Toni, she's amazing, the performance of a lifetime." Steve remembered the shoot in a positive way as well. "It was a great experience."

The production designer also used Utah, where the film was shot, as inspiration for the set.

(at around 20 mins) Disassociative Identity Disorder, the mental illness Annie claims her mother suffered from in the group therapy scene, is also the condition diagnosed on the lead subject in the movie Split (2016). The movies have the same producer.

Hereditary's production designer and costume designer also worked on A24's First Reformed (2017).

The miniature houses become almost a character in the film. When Steve initially met with Ari Aster, he discovered that the debut director had already created a laundry list of the miniature scenes he needed for the movie.

Mallory Bechtel's debut.

Ari Aster: (at around 1h 23 mins) the voice on the phone calling Annie about her exhibit date at the Archer Gallery.

During the support meeting, Annie recounts her brother's suicide at age 16, and states that his suicide note blamed their mother (Ellen) for "putting people inside him." Though Annie chalks this up to his schizophrenia, it could very well be that Ellen originally attempted to conjure Paimon through her own son. His death (and her failure to summon Paimon) would then explain why Ellen put so much pressure on Annie to have children, and why Charlie stated early on in the film that her grandmother wished she was a boy.

(at around 1h 35 mins) In an interview, Alex Wolff explains that he wanted to actually break his own nose for the scene where his character slams his head into a desk. Director Ari Aster respectfully declined that offer and told Wolff they'd give him a soft, cushioned desk for the scene. When it was time for the scene to be shot, Wolff slams his head into the desk only to discover that the top was foam and the bottom was hard. He dislocated his jaw (which is a previous injury the actor has had) for the scene.

(at around 1h 2 mins) In the art store parking lot scene, the chalkboard is shown still packaged in Joan's car, showing that she had just purchased it that day prior to showing Annie the seance.

(at around 28 mins) When Peter and Charlie are on their way to the party, the cult's logo can be seen carved into the pole that later decapitates Charlie.

One way that Ari Aster pitched the film when he was first taking it out was "it's a story about a long-lived possession ritual told from the perspective of the sacrificial lamb."

The first decapitation scene is very similar to a real-life event in Marietta, GA, in 2004. A young man and his friend drove home very drunk after a party. The passenger felt he was going to be sick and stuck his head out of the window incase he needed to throw up, while the driver accidentally swerved near a pole. The pole's guy wire decapitated the passenger. The drunk driver was so drunk he did not realize his friend was decapitated and continued to drive home, park in his parents' driveway with his decapitated friend in the car, and go inside to sleep for the night.

Hereditary's advertising campaign has been credited for keeping Charlie's death a secret from viewers, notably by showing Milly Shapiro prominently in the trailer, even though Charlie is alive for only one quarter of the film. This deliberate mislead is similar to the horror classic Psycho (1960), where Janet Leigh was made to look like the star of the film, only to be murdered one-third of the way through.

The language spoken during the "invocation" that is given to Annie is a combination of Hebrew and Enochian.

(at around 1h 20 mins) Throughout the film, several words can be seen scrawled on walls. At one point, there are two words, LIFTOACH PANDEMONIUM. Liftoach is an English transliteration of the Hebrew word 'To open', Pandemonium is Latin for All Demons and is what Satan names Hell in John Milton's Paradise Lost.

Annie's mother Ellen likely tried to summon Paimon through her son Charles before his suicide, which is why he claimed she was trying to put people inside of him and was misdiagnosed with schizophrenia. Charlie was the reincarnation of Paimon, and shared a similar name with her uncle.

One of Peter's friends from underneath the bleachers can be seen at the end of the film as one of the town's secret cultists. When they are smoking at school, he is the character with a man bun and a hoodie. When the camera is slowly following Peter's feet in the treehouse, it pans over the kneeling cultist's heads. The closest one in frame is the man bun, still intact.

Charlie's diorama in the film shows headless figurines bowing to a pigeon-headed creature with a crown on its head--very similar to the ending scene of the film.

(at around 14 mins) In an early scene, the subject of free will is discussed while mentioning one of Sophocles' plays. In the same vein, Ari Aster states that the Graham Family has no say and sometimes lacks awareness concerning the events that are taking place. For Aster, the film is very Greek in that sense. And that's where the dollhouses came in. Annie creates these miniature figures and dollhouses and they served as a perfect metaphor for the situation.

The symbol that's shown throughout the film, particularly on the necklace that Annie and her mother wear, is the real seal of the demon Paimon as shown in old texts of demonology.

(at around 4 mins) During her funeral speech Annie mentions that there are many strangers at the ceremony. It is later revealed that her mother was a cult member. The strangers at the funeral were members of the cult, some of whom can be seen in and around the house during the film's final act.

(at around 1h 35 mins) In one of the scenes in Peter's classroom, the teacher is talking about the sacrifice of Iphigenia, Agamemnon's daughter. Both Iphigenia and Charlie are daughters who were sacrificed in hopes of bringing forth a great event; one being victory against the Trojans and the other the bringing forth of Paimon.

The script was originally written to take place in a snowy landscape in the mountains, but due to cast availability they had to shoot in May/June, so they decided to "embrace the green" and look at the lush, green, springtime as emblematic of the awakening and rebirth of the cult.

(at around 30 mins) During the party scene, just as Peter enters the bedroom to smoke weed, some kids are watching a black and white video on a laptop of someone being beheaded on a guillotine - foreshadowing the film's multiple beheadings.

Milly Shapiro's most memorable moment was her stunt scene during the car accident where she was tethered to the car going 30 mph while she was hanging out of it--said it felt like a roller coaster.

At the end when the life-sized figurine of the demon Paimon is shown, the fingers of its right hand are positioned in a way that Jesus is often portrayed as doing in medieval paintings (pointer finger and middle finger out and together, other two fingers curled in a fist, and thumb parallel but slightly curved), but on Paimon, he's holding it upside down. The medieval and ancient hand gesture is used as a representation of Jesus, so like crosses being inverted, Paimon is using this to disrespect Jesus. Also, Paimon is wearing a halo with rays coming out of it like a sun. This halo is also seen in depictions of Jesus, thus meaning those worshiping Paimon believe he is the true savior.

The filmmakers had to fireproof almost everything in the room (furniture, walls, wardrobe) during the scene where Steve lights on fire.

For Ari Aster, the film itself is a running metaphor for family trauma and grief. It is operating all the way through and at the end, the movie is still about how trauma can utterly transform a person, and not necessarily for the better.

When Steve is looking through Charlie's book, he finds a picture of a pidgeon wearing a crown. The crown is in the exact same shape as Paiman's symbol.

(at around 1h 55 mins) Toni Collette wore a prosthetic neck and used a piano string for the scene where she saws her head off. It is made to look like a wire saw, which, due to its light weight and portability, is commonly carried by backpackers. Considering the locale, it would be reasonable to find such an item in an attic.

The ominous song at the end of the film is a special rendition of a song called "Zadok the Priest", written by George Frideric Handel in 1727 for the coronation of King George II.

In the opening shot, a life rune (upside down peace sign) can be seen constructed into the side of the tree house. The life rune symbolizes birth and beginnings. The appearance of the life rune signifies the beginning of the story and foreshadows the tree house as the location of Paimon's rebirth. At around 1 hour 54 min, a death rune (right side up peace sign) can been seen constructed into corner of the attic wall. The death rune symbolizes death and endings. The appearance of the death rune signifies the end of the story.

According to Ari Aster, with Hereditary, he wanted to make a film about the corrosive effects of trauma on a family unit and he also knew that he wanted to make a film that had sort of an ouroboros quality about a family that's basically eating itself in its grief. Ultimately, Hereditary is a film that was seriously tackling these issues and operating almost as a meditation on these things, while at the same time functioning as an exciting genre film that hopefully delivers.

Steve Newburn and his team also built an animatronic puppet of the family's 13-year-old daughter Charlie for her decapitation by telephone pole. This scene led to the makeup team's biggest challenge on the show. Originally, the car Charlie rode in was meant to be mounted on a track that would lead it and the animatronic puppet into the telephone pole. But changes meant that the effect had to be performed by a fully operational vehicle driving at sixty miles an hour! For the gag, a collapsible inner skull was built. This skull was meant to mirror the damage created on another "Charlie" head that was built to represent the aftermath of the accident. Tests were carried out in the makeup shop using a baseball bat to simulate the telephone pole's impact. Even without the planned track guiding the car, the effect went off perfectly. "The driver, he nailed it the first time." Steve also said that it looked fantastic but, "They (only) used a few frames of it. It was a little too disturbing."

The smiling man from the grandmother's funeral can be seen in a dark doorway towards the end of the movie.

Anticipating the criticism on why Charlie carelessly ate a nut-filled chocolate cake slice knowing she's allergic to nuts at the party scene, Ari Aster wrote the film in a way that one can interpret that Charlie is endangering herself because the Demon Paimon is influencing her and trying to get her killed. Despite this, the film still received criticism on why Annie didn't make Charlie bring an Epi Pen with her or why Peter wasn't more careful with Charlie at the party.

There are many clues, as to Peter being the one who is the desired host for Paimon. Peter was the one who accidentally killed Charlie, Annie expresses constant fear and anger towards Peter (to the point where he asks Annie why she is afraid of him) and finally because Joan yells at Peter across the schoolyard, saying "I expel you" and "get out", hoping to bring Paimon in.

There's a good deal of loud sound effects and music in the sound track. This is actually fitting to the demon Paimon, who is described as arriving with loud music and cymbals crashing.

(at around 16 mins) Charlie is eating a Dove candy bar when she cuts off the bird's head.

Hereditary has several similarities with another A24 film, The Witch (2015), despite a different writer and director. Both films depict struggling families suffering from extreme grief and being targeted by Satanic cults, both were filmed near woods, and both end with the oldest child in the family being the presumed sole survivor and encountering the cults that harmed them.

During the therapy session Annie tells of a troubled family history that she had largely kept to herself, because she did not want to "put more stress on the family". It is suggested that the family had been under the influence of the cult for a long time and hence that Annie was the one suffering for the longest time. During the film's finale, Peter gets to see with his own eyes what had been manipulating his mother all those years. The song playing over the end credits, "Both sides now," thematically relates to this series of events. The song contains the line "I've looked at life from both sides now" which could suggest that Peter was now able to see things from his mother's point of view. The song also contains the line "Tears and fears and feeling proud, to say I love you right out loud" which could suggest, that Peter finally understood that his mother actually did care for him and now was able to return those feelings, in spite of all he had been put through.

The use of a piano wire for Annie's self-inflicted decapitation is foreshadowed moments before by the piano being tipped onto its side in the living room while Peter surveys the scene of his dead father.

The film contains many uses of birds as symbolism and imagery, best example is when Charlie cuts off a dead pigeon's head to create a makeshift toy out of it, along with the rest of the bird themed toys in her bedroom. Charlie herself has many bird characteristics, such as her small facial features, her sweet tooth and love of chocolate and her clucking noise.

(at around 16 mins) Early in the film, Charlie cuts off an already-dead pigeon's head outside her school. This foreshadows Charlie's accidental decapitation, and the beheading of several other characters.

When she first meets Joan, Annie talks about how she was sleepwalking and covered Peter and Charlie in paint-thinner, almost burning them to death. Later in the film, she accidentally burns Steve to death.

One of the realistic and disturbing makeups that Steve Newburn and his crew produced was a broken nose and split lip for when the couple's teenage son Peter smashes his face into his school desk. The prosthetics were cast from silicone and the desk itself had a soft top provided by the props department. There are several decapitation scenes in Hereditary. Steve Newburn said, "We did an entire prosthetic gag for Toni Collette." This was a scene where Annie cut off her own head with piano wire.

The makeup team supplies other severed heads and bodies, some rotted, that appear later in the film. They also provided the production with dead bird bodies and other assorted animals for the daughter Charlie to behead. She would then carry these trophies around in a box. Also, during the shoot, Steve Newburn and crew produced minor prosthetics for the day-to-day trauma that the characters suffered. These were handed off to the on-set makeup crew led by department head Greg T. Moon and key makeup artist Abigail Spencer.

Annie Graham (Toni Collette) says her mom had Disassociative Identity Disorder, a condition which was the theme of Collette's Showtime series The United States of Tara (2009).